*{margin: 0px;padding: 0px;}
li{list-style: none;}
a{text-decoration: none;color: black;}

 #box{
     width: 1100px;
     margin:auto;
     padding-top:10px; 
     height: 30px;
 }
 .nav>li{
     float: right;
     width: 100px;
     height: 30px;
     position: relative;
     padding-bottom: 10px;
     margin-left:10px;
 }
 .nav>li:hover>.nav_2{
    display: block;
   }
 .nav>li>a{
  display: block;
  height: 30px;
  text-align: center;
  line-height: 30px;
 }
 .nav>li>a:hover{
  background-color: #ff0000;
  border-radius: 5px;
  color: #fff;
 }
 .nav>.boxOneLi{
  background-color: #ff0000;
  border-radius: 5px;
  padding-bottom: 0;
 }
 .boxOneLi>a{
    color: #fff;
 }
 .nav_2{
  width: 140px;
  border:1px solid #666;
  position: absolute;
  left: -20px;
  top: 40px;
  display: none;
  background-color: #fff;
 }
 .nav_2>dd{
  background-color: #f0f0f0;
  text-align: center;
  line-height: 30px;
  margin-top: 1px;
 }
 .nav_2>dd:hover{ 
    background-color: #fff;
 }
